Boat seat



FIG. 1 is a front, left perspective view of my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a right side view thereof, the holes shown in broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 4 is a left side view thereof, the holes shown in broken lines are for illustrative purposes only and form no part of the claimed design; and,

FIG. 5 is a top view thereof, the bottom and back views being non-ornamental and not part of this design. 

The ornamental design for a boat seat, as shown and described. 